Lecture 1 - Introduction Flashcards
What is microbiology?
the study of small organisms called microorganisms or microbes that are too small to be seen with the naked eye
what are microbes?
small organisms that are too small to be seen with the naked eye
what are examples of microbes we come across?
covid 19 virus, RSV virus, yeast, mold, yogurt, kimchi
all organisms can be divided into what 3 domains of life?
bacteria
archaea
eukarya
all organisms are made up of cells, what is it called when theres 1 cell and more than 1 cell?
1 cell = unicellular
>1 cell = multicellular
the bacteria and archaea domain contains what organisms? are they multicellular or unicellular?
prokaryotes with prokaryotic cells; unicellular
what are the organisms under the Eukarya domain? are they unicellular or multicellular?
eukaryotes with eukaryotic cells; they are both unicellular and multicellular
T/F: microbes are present in all 3 domains of life
TRUE
in the bacteria domain, what type of cells are present?
prokaryotic cells and they are unicellular
in the archaea domain, what type of cells are present?
prokaryotic cells and they are unicellular
in the eukarya domain, what type of cells are present?
eukaryotic cells and they are uni or multicellular
all organisms are made up of cells, what is it called when theres 1 cell and more than 1 cell?
1 cell = unicellular
>1 cell = multicellular
what are the 4 kingdoms under the eukarya domain?
- The protists kingdom
- Plantae kingdom
- Fungi kingdom
- Animalia kingdom
what is contained in the protists kingdom?
a. protozoa (unicellular)
b. algae (uni or multicellular)
what is contained in the fungi kingdom?
a. yeast (unicellular)
b. mold (multicellular)
what is contained in the animal kingdom?
a. helminths (multicellular)
do prokaryotes have a nucleus?
no, they have no compartments and their DNA is naked. like an empty office
do eukaryotes have a nucleus?
yes, they have a nucleus and compartments. there is DNA within the nucleus. like an office w/ cubicles
are viruses microbes?
yes
do viruses belong to a domain?
NO
where do viruses belong?
to the acellular infection agents
what are the two microbial categories?
- Living: with organisms
- Non-living: with acellular infectious agents
How is an acellular infectious agent different from an organism? Give an example of
each.
Acellular infectious agents are different from an organism because they are non-living and they don’t have a typical cell structure. An example of an acellular infectious agent is a virus. An example of an organism is algae.
what is within the non-living acellular infectious agents category?
viruses, viroids, and prions
how many micrometers (um) can we see with the naked eye?
100-200 um (micrometers)
how small is a bacteria?
1 um (micrometer) which is 1 meter divided by 1 million
how small is a virus?
20-200 nanometers (nm), which is when we divide a micrometer by 1 million again
how small is a eukaryote?
5-50 um
how small is a prokaryote?
0.3-2 um
T/F: most microbes can’t be seen with the naked eye except for one exception that was recently discovered
True
what technique do we use to name microbes?
binomial nomenclature
what is the binomial nomenclature?
the genus + the species AND it is italicized
what is an example of naming a microbe?
Escherichia coli or E. coli (italicized)
do we follow this naming system for acellular infectious agents?
no, we do not. for example, HIV
where are microbes?
everywhere (ubiquitous) - in soil, air, water, organisms, etc.
what is spontaneous generation?
that living things can arise from non-living matter via a “vital force”
what did francesco redi provide evidence against?
in 1668 he provided evidence against spontaneous generation. people believed his theory for microorganisms but no microorganisms
what was redi’s experiment?
he had a piece of meat in an unsealed flask, and that created living things.
he had a sealed flask with the meat, and no living things arises.
then he had a flask covered with gauze to allow air to come in, and again no living things arises.
did john needham provide evidence in support of spontaneous generation?
yes, he did in 1749. He did so by briefly boiling broth to kill all organisms and sealed the north flask to allow for gas exchange, but he still observed the spontaneous growth of organisms.
how did lazarro spallanzani provide evidence against spontaneous generation?
in 1776 he provided evidence against it by heating broth longer to kill all organisms, and sealed the flask for no gas exchange, and he did not observe spontaneous generation. so no growth of organisms
what did he say about air carrying microbes?
he said that air carries microbes into the flask which multiply to make more microbes. people said that he boiled too much to destroy the “vital force” and sealed too tightly which kept away the “vital force”
what did Louis Pasteur provide in evidence against spontaneous generation?
he kept the “swan-necked” flasks upright and there was no microbial growth despite being open to air. when the flask was titled, dust from the bend in the neck seeped back into the flask and made there be microbial growth, so boiling did not kill the vital force.
How did Pasteur disprove spontaneous generation? Explain the scientific
process – hypothesis, prediction, experiment, and conclusion.
Pasteur disproved it by using a swan-necked flask and he saw no microbial growth. This is where biogenesis came from, which is when living things arise from living things. He hypothesized that spontaneous generation wasn’t true. His prediction was that if he used the swan-necked flask and kept them upright, no microbial growth would appear despite being open to the air. And his experiment proved his prediction right. When the flask was titled, dust from the bend in the neck seeped back into the flask and created microbial growth. So is conclusion was that boiling did not kill the vital force.
Louis Pasteur came up with biogenesis, what is that?
that living things only arise from living things
who was the first person to build a microscope?
The first person to build a microscope was Robert Hooke in 1665.
who was the first person to observe microbes?
The first person to observe microbes was Antonie Van Leeuwenhoek in 1676.
where are bacteria present?
soil, water, air, organisms